Nonlinear postbuckling of high-order shear deformable ternary silica nanoparticle/carbon nanotube/polymer nanocomposite annular sector plates with various boundary conditions

Abstract

In this paper, the nonlinear postbuckling behavior of high-order shear deformable polymer nanocomposite annular-sector plates containing carbon nanotube (CNT)/silica nanoparticle (SiO2) hybrid nanofillers is investigated. The study employs a hierarchical approach by integrating finite element micromechanical modeling to determine the effective material properties of ternary CNT/SiO2/polymer nanocomposites, along with a geometrically nonlinear plate formulation incorporating von Kármán-type nonlinear strain-displacement relations. The governing equations are derived and numerically solved using the variational differential quadrature (VDQ) scheme to evaluate the critical buckling loads as well as postbuckling equilibrium paths under in-plane compressive loading. Key parameters such as the content, geometry, and dispersion pattern of nanofillers, nanofiller/polymer interphase effects, and boundary constraints are systematically studied. Results reveal that the addition of nanofillers enhances the critical buckling load and postbuckling stability, with higher CNT aspect ratios, smaller SiO2 diameters, and aligned dispersion pattern showing superior performance. Moreover, the destructive effects of nanofiller agglomeration can be mitigated by breaking up the agglomerates, and the formation of robust interphase regions between the nanofillers and polymer further improves load-bearing capacity and stability. Boundary conditions play an important role in affecting the structural response, with fully clamped edges demonstrating the maximum load-bearing capacity and simply supported edges the lowest. © 2025 Elsevier B.V.